Additives for minimizing injector fouling and valve deposits and their uses

ABSTRACT

This invention relates to compositions for use in minimizing injector fouling, such as in fuel injectors, and preventing deposits in valves, such as intake valves, comprising (a) a Mannich detergent and (b) a succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to compositions for use in minimizing injector fouling, such as in fuel injectors, and preventing deposits in valves, such as intake valves, comprising (a) a Mannich detergent and (b) a particular succinimide.

2. Background Art

The use of conventional fuels without detergent and corrosion-inhibiting additives promotes the accumulation of deposits in the induction system, in particular at the injectors, which become fouled, or even in the combustion chamber, resulting from the presence of polar aromatic compounds and traces of lubricants.

The accumulation of deposits has a detrimental effect on the quality of evaporation of the fuel, which causes an increase in consumption, an increase in the emission of pollutants and of smoke, which is significantly greater during acceleration, and, finally, an increase in noise.

To overcome this problem of fouling of the engine, it is possible to periodically clean the fouled components and particularly the injectors. However, in the long run, this method becomes very expensive.

Another method for reducing fouling by deposits in engines, including the injectors, is to utilize detergents that are capable of being absorbed on the metal surfaces to prevent the formation of deposits and/or to remove the deposits already formed by cleaning the injectors. Examples of such detergents are the products resulting from the condensation of polyalkenyl succinic anhydrides with polyamines, such as tetraethylenepentamine (“TEPA”), described in U.S. Pat. No. 3,172,892.

BRIEF SUMMARY OF THE INVENTION

The compositions of the invention may be utilized as detergents to prevent formation of deposits and/or remove already formed deposits in injectors, such as fuel injectors, and/or valves, including intake valves.

In one aspect, the disclosure herein is directed to novel fuel compositions comprising, or consisting essentially of, (a) a Mannich detergent and (b) a succinimide that is a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

In another aspect, the disclosure herein is directed to novel gasoline compositions comprising, or consisting essentially of, (a) a hydrocarbon, (b) a Mannich detergent and (c) a succinimide that is a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

In yet another aspect, the disclosure herein is directed to gasoline additive compositions comprising, or consisting essentially of, (a) a Mannich detergent and (b) a succinimide that is a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

In still yet another aspect, the disclosure herein is directed to a method of preventing injector fouling, such as in a fuel injector, comprising contacting the injector with a composition comprising, or consisting essentially of, (a) a Mannich detergent and (b) a succinimide that is a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

In another aspect, the disclosure herein is directed to a method of preventing deposits in a valve, such as an intake valve comprising contacting the valve with a novel composition comprising, or consisting essentially of, (a) a Mannich detergent and (b) a succinimide that is a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

In yet another aspect, the disclosure herein is directed to an engine comprising a novel composition comprising, or consisting essentially of, (a) a Mannich detergent and (b) a succinimide that is a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure is directed to novel fuel compositions comprising, or consisting essentially of, (a) a Mannich detergent and (b) a succinimide that is a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

As used herein, the singular forms “a” or “an” or “the” include plural references unless the context clearly dictates otherwise. For example, reference to “an alkenyl-substituted succinic anhydride” includes a composition comprising only one specific alkenyl-substituted succinic anhydride, as well as a composition comprising a mixture of alkenyl-substituted succinic anhydrides.

As used herein, the term “about” encompasses the range of experimental error that occurs in any measurement.

As used herein, the term “present in the reaction” indicates that the starting materials utilized to generate the succinimide included in the novel composition are mixed and/or blended under conditions that should result in the formation of the succinimide.

The invention provides both a gasoline additive concentrate and a finished or additized gasoline fuel product.

Mannich Detergents

The Mannich detergents utilized in the novel compositions can be obtained by reacting an alkyl-substituted hydroxyaromatic compound, an aldehyde and an amine in a Mannich condensation reaction, as described herein.

Examples of suitable alkyl-substituted hydroxyaromatic compounds that may be used in forming the Mannich detergents, include, but are not limited to, polypropylphenol (formed by alkylating phenol with polypropylene), polybutylphenols (formed by alkylating phenol with polybutenes and/or polyisobutylene), polybutyl-co-polypropylphenols (formed by alkylating phenol with a copolymer of butylene and/or butylene and propylene), polypropylcresol (formed by alkylating cresol with polypropylene), polybutylcresols (formed by alkylating cresol with polybutenes and/or polyisobutylene), polybutyl-co-polypropylcresols (formed by alkylating cresol with a copolymer of butylene and/or butylene and propylene). Other similar long-chain alkylphenols may also be used. Examples include, but are not limited to, phenols or cresols alkylated with copolymers of butylene and/or isobutylene and/or propylene, and one or more mono-olefinic comonomers copolymerizable therewith (e.g., ethylene, 1-pentene, 1-hexene, 1-octene, 1-decene, etc.) where the copolymer molecule contains at least 50% by weight, of butylene and/or isobutylene and/or propylene units. The comonomers polymerized with propylene or said butenes may be aliphatic and can also contain non-aliphatic groups, e.g., styrene, o-methylstyrene, p-methylstyrene, divinyl benzene and the like. Thus, the resulting polymers and copolymers used in forming the alkyl-substituted hydroxyaromatic compounds are substantially aliphatic hydrocarbon polymers.

In one embodiment, the alkyl-substituted hydroxyaromatic compound is polybutylphenol (formed by alkylating phenol with polybutylene). In another embodiment, the alkyl-substituted hydroxyaromatic compound is polybutylcresol (formed by alkylating cresol with polybutylene). Unless otherwise specified herein, the term “polybutylene” is used in a generic sense to include polymers made from “pure” or “substantially pure” 1-butene or isobutene, and polymers made from mixtures of two or all three of 1-butene, 2-butene and isobutene. Commercial grades of such polymers may also contain insignificant amounts of other olefins. So-called high reactivity polybutylenes having relatively high proportions of polymer molecules having a terminal vinylidene group, formed by methods such as described, for example, in U.S. Pat. No. 4,152,499 and W. German Offenlegungsschrift 29 04 314, are also suitable for use in forming the long chain alkylated phenol or cresol reactant.

The alkylation of the hydroxyaromatic compound may be performed in the presence of an alkylating catalyst such as BF₃ at a temperature in the range of about 50 to about 200° C. The long chain alkyl substituent groups on the benzene ring of the phenol or cresol molecule are derived from polyolefin having an average molecular weight of about 500 to about 3000, as determined by gel permeation chromatography (“GPC”). In one embodiment, the polyolefin has an average molecular weight of about 500 to about 2000.

In one embodiment, the polyolefin used to derive the long chain alkyl substituent groups on the benzene ring of the phenol or cresol molecule has a polydispersity (weight average molecular weight/average molecular weight) of about 1 to about 4, as determined by GPC. In another embodiment, the polyolefin used to derive the long chain alkyl substituent groups on the benzene ring of the phenol or cresol molecule has a polydispersity of about 1 to about 2.

The Mannich detergent may be made from a long chain alkylphenol or a long chain alkylcresol. However, other phenolic compounds may be used including, but not limited to, high molecular weight alkyl-substituted derivatives of resorcinol, hydroquinone, catechol, xylenol, hydroxydiphenyl, benzylphenol, phenethylphenol, naphthol, and tolyinaphthol.

In one embodiment, the Mannich detergent is synthesized from a polyalkylphenol or a polyalkylcresol, such as, but not limited to, polypropylphenol, polybutylphenol, polypropylcresol, and polybutylcresol. In another embodiment, the Mannich detergent is synthesized from a polyalkylphenol or polyalkylcresol containing an alkyl substituent group with an average molecular weight of about 650 to about 1500. In another embodiment, the Mannich detergent is synthesized from a polyalkylphenol or polyalkylcresol containing an alkyl substituent group with an average molecular weight of about 800 to about 1300.

In one embodiment, the Mannich detergent is synthesized from a polyalkylcresol, such as, but not limited to, polypropylcresol and polybutylcresol. In another embodiment, the Mannich detergent is synthesized from a polyalkylcresol containing an alkyl substituent group with an average molecular weight of about 650 to about 1500. In yet another embodiment, the Mannich detergent is synthesized from a polyalkylphenol or polyalkylcresol containing an alkyl substituent group with an average molecular weight of about 800 to about 1300.

In one embodiment, the Mannich detergent is synthesized from polybutylcresol. In another embodiment, the Mannich detergent is synthesized from polybutylcresol containing an alkyl substituent group with an average molecular weight of about 650 to about 1500. In yet another embodiment, the Mannich detergent is synthesized from polybutylcresol containing an alkyl substituent group with an average molecular weight of about 800 to about 1300.

Suitable amines used in the reaction to generate the Mannich detergent include, but are not limited to, alkylene polyamines having at least one suitably reactive primary or secondary amino group in the molecule. Other substituents such as, hydroxyl, cyano, and amido may also be present in the polyamine.

In one embodiment, the alkylene polyamine used in the reaction generating the Mannich detergent is a polyethylene polyamine. Suitable alkylene polyamine reactants include, but are not limited to, ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, hexaethylene heptamine, heptaethylene octamine, octaethylene nonamine, nonaethylene decamine, decaethylene undecamine, and mixtures of such amines having nitrogen contents corresponding to alkylene polyamines of the formula H₂N—(CH₂—CH₂—NH—)_(n)H, where n is an integer of from 1 to 10. Corresponding propylene polyamines are also suitable reactants. The alkylene polyamines may be obtained by the reaction of ammonia and dihalo alkanes, such as dichloro alkanes. Thus, the alkylene polyamines obtained from the reaction of 2 to 11 moles of ammonia with 1 to 10 moles of dichloro alkanes having 2 to 6 carbon atoms and the chlorines on different carbon atoms are suitable alkylene polyamine reactants.

In another embodiment, the amine used in the reaction to generate the Mannich detergent is an aliphatic diamine having one primary or secondary amino group and one tertiary amino group in the molecule. Examples of suitable polyamines include, but are not limited to, N,N,N″,N″-tetraalkyldialkylenetriamines (two terminal tertiary amino groups and one central secondary amino group), N,N,N′,N″-tetraalkyltrialkylenetetramines (one terminal tertiary amino group, two internal tertiary amino groups and one terminal primary amino group), N,N,N′,N″,N′″-pentaalkyltrialkylenetetramines (one terminal tertiary amino group, two internal tertiary amino groups and one terminal secondary amino group), N,N-dihydroxyalkyl-alpha, omega-alkylenediamines (one terminal tertiary amino group and one terminal primary amino group), N,N,N′-trihydroxyalkyl-alpha, omega-alkylenediamines (one terminal tertiary amino group and one terminal secondary amino group), tris(dialkylaminoalkyl)aminoalkylmethanes (three terminal tertiary amino groups and one terminal primary amino group), and like compounds, wherein the alkyl groups are the same or different and may contain no more than about 12 carbon atoms each, and which preferably contain from 1 to 4 carbon atoms each. In one embodiment, the alkyl groups are methyl and/or ethyl groups. In another embodiment, the polyamine reactants are N,N-dialkyl-alpha, omega-alkylenediamine, such as those having from 3 to about 6 carbon atoms in the alkylene group and from 1 to about 12 carbon atoms in each of the alkyl groups, which most preferably are the same but which can be different. In yet another embodiment, the polyamine reactant is N,N-dimethyl-1,3-propanediamine.

Examples of polyamines having one reactive primary or secondary amino group that can participate in the Mannich condensation reaction, and at least one sterically hindered amino group that cannot participate directly in the Mannich condensation reaction to any appreciable extent include, but are not limited to, N-(tert-butyl)-1,3-propanediamine, N-neopentyl-1,3-propanediamine, N-(tert-butyl)-1-methyl-1,2-ethanediamine, N-(tert-butyl)-1-methyl-1,3-propanediamine, and 3,5-di(tert-butyl)aminoethylpiperazine.

In one embodiment, the amine included in the reaction to synthesize the Mannich detergent is dibutyl amine. Also useful herein to synthesize the Mannich detergent are dimethyl amine, diethyl amine and dipropyl amine. Also useful herein are mixed alkyl amines, such as ethyl-propylamine, propyl-butylamine, and mixtures of mono and dialkyl amines. Monoamines are also useful herein.

Examples of aldehydes that may be used in preparing the Mannich detergents include, but are not limited to, aliphatic aldehydes. In one embodiment, the aldehyde is formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, caproaldehyde, heptaldehyde, or stearaldehyde. In another embodiment, the aldehyde is an aromatic aldehyde, such as benzaldehyde or salicylaldehyde. In yet another embodiment, the aldehyde is a heterocyclic aldehyde, such as furfural or thiophene aldehyde. In still yet another embodiment, a formaldehyde-producing reagent, such as paraformaldehyde or an aqueous formaldehyde solution, such as formalin is used. In another embodiment, the aldehyde is formaldehyde or formalin.

The condensation reaction among an alkyl-substituted hydroxyaromatic compound, an amine and an aldehyde may be conducted at a temperature in the range of about 40° C. to about 200° C. The reaction may be conducted in bulk (no diluent or solvent) or in a solvent or diluent. Water is evolved and may be removed by azeotropic distillation during the course of the reaction. In one embodiment, the Mannich detergents are formed by reacting an alkyl-substituted hydroxyaromatic compound, an amine and an aldehyde in the molar ratio of 1.0:0.5-2.0:1.0-3.0, respectively.

Succinimides

(i) Alkenyl-Substituted Succinic Anhydride

The alkenyl-substituted succinic anhydrides that are reacted with an amine-containing polyalkylene polymer to yield the reaction product included in the compositions disclosed herein, generally have an average molecular weight of about 250 to about 3000. In one embodiment, the average molecular weight of the alkenyl-substituted succinic anhydride is about 500 to about 2500. In another embodiment, the average molecular weight of the alkenyl-substituted succinic anhydride is about 600 to about 2000. In yet another embodiment, the average molecular weight of the alkenyl-substituted succinic anhydride is about 750 to about 1500. In still yet another embodiment, the average molecular weight of the alkenyl-substituted succinic anhydride is about 900 to about 1200. In another embodiment, the average molecular weight of the alkenyl-substituted succinic anhydride is about 1050.

In one embodiment, the alkenyl-substituted succinic anhydride includes an alkenyl-substituent group containing an average of at least about 30 carbon atoms. In another embodiment, the alkenyl-substituent group contains an average of at least about 40 carbon atoms. In yet another embodiment, the alkenyl-substituent group has an average of at least about 50 carbon atoms. In still yet another embodiment, the alkenyl-substituent group contains an average of at least about 60 carbon atoms. In another embodiment, the alkenyl-substituent group contains an average of at least about 75 carbon atoms. In yet another embodiment, the alkenyl-substituent group contains an average of at least 100 carbon atoms.

In one embodiment, the alkenyl-substituent group contains an average number of carbon atoms of about 30 to about 150. In another embodiment, the alkenyl-substituent group contains an average number of carbon atoms of about 40 to about 100. In yet another embodiment, the alkenyl-substituent group contains an average number of carbon atoms of about 50 to about 90. In still yet another embodiment, the alkenyl-substituent group contains an average number of about 80 carbon atoms.

In one embodiment, the alkenyl-substituent group has an average molecular weight about 200 to about 2950. In another embodiment, the alkenyl-substituent group has an average molecular weight of about 450 to about 2450. In yet another embodiment, the alkenyl-substituent group has an average molecular weight of about 550 to about 1950. In still yet another embodiment, the alkenyl-substituent group has an average molecular weight of about 700 to about 1450. In another embodiment, the alkenyl-substituent group has an average molecular weight of about 850 to about 1150. In yet another embodiment, the alkenyl-substituent group has an average molecular weight of about 950.

Optionally, the alkenyl-substituent group may include one or more carbon-carbon double bonds.

Non-limiting examples of suitable alkenyl-substituent groups include polyethylene, polypropylene, polybutene, poly(1-hexene), polyisobutene, or poly(1-butene), or mixtures of poly(ethylene/propylene), poly(ethylene/butene), poly(propylene/1-hexene), poly(isobutene), or poly(1-butene). The alkenyl-substituent groups may consist of a mixture of any of these substituent groups and may optionally include molecules of differing numbers of carbon atoms and/or molecular weights. Additionally, the alkenyl-substituent groups may optionally be substituted.

In one embodiment, the alkenyl-substituent group is poly(isobutene). In another embodiment, the alkenyl-substituent group is poly(isobutene) having an average molecular weight of about 200 to about 2950. In yet another embodiment, the alkenyl-substituent group is poly(isobutene) having an average molecular weight of about 450 to about 2450. In still yet another embodiment, the alkenyl-substituent group is poly(isobutene) having an average molecular weight of about 550 to about 1950. In another embodiment, the alkenyl-substituent group is poly(isobutene) having an average molecular weight of about 700 to about 1450. In yet another embodiment, the alkenyl-substituent group is poly(isobutene) having an average molecular weight of about 850 to about 1150. In still yet another embodiment, the alkenyl-substituent group is poly(isobutene) having an average molecular weight of about 950.

A specific example of a suitable alkenyl-substituted succinic anhydride includes, but is not limited to, polyisobutylene succinic anhydride (“PIBSA”). In one embodiment, PIBSA has an average molecular weight of about 250 to about 3000. In another embodiment, PIBSA has an average molecular weight of about 500 to about 2500. In yet another embodiment, PIBSA has an average molecular weight of about 600 to about 2000. In still yet another embodiment, PIBSA has an average molecular weight of about 750 to about 1500. In another embodiment, PIBSA has an average molecular weight of about 900 to about 1200. In yet another embodiment, PIBSA has an average molecular weight of about 1050.

In one embodiment, PIBSA has a polyisobutenyl group containing an average of at least about 30 carbon atoms. In another embodiment, PIBSA has a polyisobutenyl group containing an average of at least 40 carbon atoms. In yet another embodiment, PIBSA has a polyisobutenyl group containing an average of at least about 50 carbon atoms. In still yet another embodiment, PIBSA has a polyisobutenyl group containing an average of at least about 60 carbon atoms. In another embodiment, PIBSA has a polyisobutenyl group containing an average of at least about 75 carbon atoms. In yet another embodiment, PIBSA has a polyisobutenyl group containing an average of at least 100 carbon atoms.

In one embodiment, PIBSA has a polyisobutenyl group containing an average number of carbon atoms of about 30 to about 150. In another embodiment, PIBSA has a polyisobutenyl group containing an average number of carbon atoms of about 40 to about 100. In yet another embodiment, PIBSA has a polyisobutenyl group containing an average number of carbon atoms of about 50 to about 75. In still yet another embodiment, PIBSA has a polyisobutenyl group containing an average number of carbon atoms of about 60.

Methods of preparing the alkenyl-substituted succinic anhydride are well known to persons of ordinary skill in the art. For example, alkenyl-substituted succinic anhydrides may be prepared using a thermal process known as “ene chemistry” (see, e.g., U.S. Pat. No. 3,361,673) and a chlorination process (see, e.g., U.S. Pat. No. 3,172,892).

(ii) Amine-Containing Polyalkylene Polymer

The amine-containing polyalkylene polymer is a molecule having a straight or branched chain with at least one tertiary amine. The polyalkylene group of the amine-containing polyalkylene polymer will preferably be relatively free of aliphatic unsaturation, i.e., ethylenic and acetylenic, particularly acetylenic unsaturation. The polyalkylene group of the amine-containing polyalkylene polymer will generally be an unbranched chain.

In one embodiment, the amine-containing polyalkylene polymer has an average molecular weight of about 100 to about 750. In one embodiment, the amine-containing polyalkylene polymer has an average molecular weight of about 150 to about 650. In another embodiment, the amine-containing polyalkylene polymer has an average molecular weight of about 150 to about 500. In yet another embodiment, the amine-containing polyalkylene polymer has an average molecular weight of about 400 to about 600.

In one embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 3.0 to about 18.0. In another embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 3.5 to about 17.5. In yet another embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 3.0 to about 7.0. In still yet another embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 8.0 to about 16.0. In another embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 8.5 to about 15.5. In yet another embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 9.0 to about 15.0.

In one embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 8.5 to about 9.5. In another embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 9.5 to about 10.5. In yet another embodiment, the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 14.5 to about 15.5.

In one embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 3 nitrogen atoms per molecule. In another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 4 nitrogen atoms per molecule. In yet another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 5 nitrogen atoms per molecule. In still yet another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 6 nitrogen atoms per molecule. In another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 7 nitrogen atoms per molecule. In yet another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 8 nitrogen atoms per molecule. In still yet another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 9 nitrogen atoms per molecule. In another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 10 nitrogen atoms per molecule. In yet another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 11 nitrogen atoms per molecule. In still yet another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 12 nitrogen atoms per molecule. In another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 13 nitrogen atoms per molecule. In yet another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 14 nitrogen atoms per molecule. In still yet another embodiment, the amine-containing polyalkylene polymer is a mixture in which the amine-containing predominant polyalkylene polymer contains at least about 15 nitrogen atoms per molecule. In another embodiment, the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 16 nitrogen atoms per molecule.

Examples of suitable amine-containing polyalkylene polymers include, but are not limited to, tetraethylenepentamine (“TEPA”), triethylenetetramine (“TETA”), pentaethylenehexamine (“PEHA”), and diethylenetriamine (“DETA”). In one embodiment, the amine-containing polyalkylene polymer is TEPA.

Method of Preparing the Succinimides

The novel compositions described herein are more effective in minimizing injector fouling and preventing deposits in valves than other detergents. One possible rationale for these results is that the novel compositions are more polar than those other detergents. The polarity of a detergent composition may be affected by various factors, including what starting materials are used, as well as the ratio of the starting components, such as the ratio of the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer used in generating the succinimide.

The alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer may be reacted at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In one embodiment, the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer may be reacted at a molar ratio of about 1.0:1.0.

Compositions

The novel compositions of this invention contain (a) a Mannich detergent and (b) a succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In one embodiment, the novel composition containing (a) a Mannich detergent and (b) a succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, is included in a fuel composition. In another embodiment, the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, are added individually to the fuel composition to yield a novel composition. In yet another embodiment, the novel composition containing (a) a Mannich detergent and (b) a succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, is formulated as an additive composition, such as a concentrate, and may optionally be added to a fuel composition before the fuel composition is contacted with an engine, such as an engine that utilizes spark-ignition fuels, an injector, including a fuel injector, and/or a valve, such as an intake valve.

When formulating a gasoline composition of this invention, the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, are each employed in an amount sufficient to minimize injector fouling, such as in a fuel injector, or preventing deposits in valves, such as in intake valves. Thus, the fuel composition will contain a minor amount of the reaction product to control or reduce formation of deposits and a major amount of a base fuel, such as a hydrocarbon.

The base fuels used in formulating the fuel compositions of the present invention include any base fuels suitable for use in the operation of spark-ignition internal combustion engines such as leaded or unleaded motor and aviation gasolines, and so-called reformulated gasolines which may contain both hydrocarbons of the gasoline boiling range and fuel-soluble oxygenated blending agents, such as alcohols, ethers and other suitable oxygen-containing organic compounds. Oxygenates suitable for use in the present invention include methanol, ethanol, isopropanol, t-butanol, mixed C₁ to C₅ alcohols, methyl tertiary butyl ether, tertiary amyl methyl ether, ethyl tertiary butyl ether and mixed ethers. Oxygenates, when used, will normally be present in the base fuel in an amount below about 25% by volume, and preferably in an amount that provides an oxygen content in the overall fuel in the range of about 0.5 to about 5 percent by volume.

In one embodiment, the base fuel comprises a hydrocarbon. In another embodiment, the hydrocarbon comprises a spark-ignition fuel. In yet another embodiment, the spark-ignition fuel comprises gasoline. In still yet another embodiment, the spark-ignition fuel comprises a blend of hydrocarbons of the gasoline boiling range and a fuel-soluble oxygenated compound.

In another embodiment, the fuel composition will contain, on an active ingredient basis, an amount of the reaction product of about 0.5 to about 500 pounds per 1000 barrels (“PTB”) of each of the ingredients. In yet another embodiment, the fuel composition will contain, on an active ingredient basis, about 2 to about 100 PTB of each ingredients. In still yet another embodiment, the fuel composition will contain, on an active ingredient basis, about 3 to about 90 PTB of each of the ingredients.

In one embodiment, the fuel composition contains about 50 to about 150 PTB of the Mannich detergent and about 1 to about 10 PTB of the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In another embodiment, the fuel composition contains about 75 to about 100 PTB of the Mannich detergent and about 2 to about 7 PTB of the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

In another embodiment, the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, may be formulated as an additive composition, such as a concentrate, and may optionally be added to a fuel composition prior to contacting the engine, such as an engine that utilizes spark-ignition fuels, an injector, including a fuel injector, and/or a valve, such as an intake valve. The Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, may be formulated in the additive composition with a carrier. In one embodiment, the carrier is a liquid carrier fluid.

In one embodiment, the additive composition contains about 20 to about 80 weight percent of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In one embodiment, the additive composition contains about 30 to about 50 weight percent of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

In another embodiment, the additive composition may contain about 20 to about 70 weight percent of the carrier. In yet another embodiment, the additive composition may contain about 30 to about 50 weight percent of the liquid carrier fluid.

In general, the weight ratio of carrier to each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, on an active ingredient basis, will usually be about 1.6:1 to about 2:1. In one embodiment, the weight ratio of carrier to each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, on an average ingredient basis, will usually be about 1.6:1 to about 1:1. The active ingredient basis excludes the weight of (i) the unreacted alkenyl-substituted succinic anhydride or the amine-containing polyalkylene polymer associated with, and remaining, in the product as produced and used, and (ii) solvent(s), if any, used in the manufacture of the Mannich detergent and/or the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, either during or after its formation but before addition of the carrier.

The proportion of the carrier used relative to each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, in the additive packages of this invention, is such that the fuel composition containing the diluted additive composition, when consumed in an engine, such as an engine that utilizes spark-ignition fuels, results in improved cleanliness as compared to cleanliness of the same engine operated on the same fuel composition except for being devoid of the carrier with the novel composition.

The carrier fluid component of the fuel and fuel additive compositions described herein can also include a first base oil derived from a gaseous source. Gaseous sources include a wide variety of materials such as natural gas, methane, C₁-C₃ alkanes, landfill gases, and the like. Such gases may be converted to liquid hydrocarbon products suitable for use as carrier fluids by a gas to liquid (GTL) process, such as the process described in U.S. Pat. No. 6,497,812, the disclosure of which is incorporated herein by reference. For the purposes of this disclosure, a “gas” or “gaseous source” means a material that is in the gaseous state at room temperature and atmospheric pressure. A “liquid” means a material that is predominantly in a liquid or fluid state at room temperature and atmospheric pressure.

Carrier fluids or oils derived from a gaseous source, hereinafter referred to as “GTL base oils,” typically have a viscosity index of greater than about 130, a sulfur content of less than about 0.3 percent by weight, contain greater than about 90 percent by weight saturated hydrocarbons (isoparaffins), typically from about 95 to about 100 wt. % branched aliphatic hydrocarbons, have a pour point of below 15 to −20° C., and have a NOACK volatility of less than about 15 weight percent, and in another embodiment a NOACK volatility of less than about 10 weight percent. The carrier oil component of the fuel composition, as described herein, may include from about 5 to about 100 percent by weight of the GTL oil with the balance of the carrier oil component being a conventional base oil.

Conventional base oils that may optionally be combined with the GTL base oil to provide a fuel composition include natural and synthetic base oils in Groups I-V as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines.

Alternatively, the proportion of the carrier used relative to each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, in the additive packages of this invention, is such that the fuel composition containing the diluted additive composition, when consumed in an injector, such as a fuel injector, results in improved cleanliness as compared to cleanliness of the same injector operated on the same fuel composition except for being devoid of the carrier with the novel composition.

Furthermore, the proportion of the carrier used relative to each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, in the additive packages of this invention, is such that the fuel composition containing the diluted additive composition, when consumed in a valve, such as an intake valves, results in improved cleanliness as compared to cleanliness of the same valve operated on the same fuel composition except for being devoid of the carrier with the novel composition.

The additive compositions used in formulating the preferred fuels of this invention can be blended into the fuel, such as a spark-ignition fluid, individually or in various sub-combinations. In one embodiment, all of the components are blended concurrently using an additive concentrate as this takes advantage of the mutual compatibility afforded by the combination of ingredients when in the form of an additive concentrate. Also, use of a concentrate reduces blending time and lessens the possibility of blending errors.

In addition to the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, the fuel compositions and/or additive concentrates may optionally contain additional components. For example, the fuel compositions and/or additive concentrates may include one or more of carrier fluids, friction modifiers, detergents, dispersants, anti-valve-seat reducing agents, combustion improvers, antioxidants, heat stabilizers, anti-icing additives, antiknock additives, corrosion inhibitors, dehazers, metal deactivators, antifoaming agents, biocides, cosolvents, package compatibilisers, lubricity additives, antistatic additives, drag reducing agents, dyes, markers, cold flow additives, demulsifiers, and the like. Similarly, the fuel compositions and/or additive concentrates may contain suitable amounts of conventional fuel blending components such as methanol, ethanol, dialkyl ethers, and the like.

One embodiment of the invention includes a method for reducing the amount of deposits of an engine which comprises contacting the engine with a fuel composition comprising a major amount of a hydrocarbon and a minor portion of a minor amount of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In another embodiment, the invention includes a method for reducing the amount of deposits of an engine that utilizes a spark-ignition fuel which comprises contacting the engine with a fuel composition comprising a major amount of a hydrocarbon and a minor portion of a minor amount of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

Another embodiment of the invention includes a method for minimizing injector fouling comprising contacting an injector with a fuel composition comprising a major amount of a hydrocarbon and a minor amount of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In yet another embodiment, the invention includes a method for minimizing injector fouling comprising contacting a fuel injector with a fuel composition comprising a major amount of a hydrocarbon and a minor amount of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In still yet another embodiment, the invention includes a method for minimizing injector fouling comprising contacting a fuel injector with a fuel composition comprising a major amount of a spark-ignition fuel and a minor amount of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

Another embodiment of the invention includes a method for preventing deposits in a valve comprising contacting a valve with a fuel composition comprising a major amount of a hydrocarbon and a minor amount of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In yet another embodiment, the invention includes a method for preventing deposits in an intake valve comprising contacting an intake valve with a fuel composition comprising a major amount of a hydrocarbon and a minor amount of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3. In still yet another embodiment, the invention includes a method for preventing deposits in an intake valve comprising contacting a fuel injector with a fuel composition comprising a major amount of a spark-ignition fuel and a minor amount of each of the Mannich detergent and the succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride with an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.

In some embodiments, the reaction between the alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and the amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3, may occur in the carrier liquid. The Mannich detergent may then be added to the carrier liquid either before or after the reaction of the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer.

In some embodiments, the preformed succinimide is blended with a suitable amount of the carrier liquid. The Mannich detergent may be blended with the carrier liquid either before or after addition of the succinimide. If desired, the reactant product can be formed in a suitable solvent or carrier liquid and then blended with an additional quantity of the same or a different carrier liquid.

In some embodiments, the Mannich detergent may be blended with the succinimide prior to either component being blended with the carrier liquid.

All patents and publications cited herein are fully incorporated by reference herein in their entirety.

EXAMPLES Example 1 Synthesis of PIBSA

178 grams maleic anhydride and 1435 grams polyisobutylene (molecular weight of 950) were added to a reactor. The reaction was heated to 235° C. and refluxed for 5 hours.

A sample of the mixture was taken and a stripped acid number was run. The target range was between 1.03 and 1.07. If the stripped acid number was lower than the target range, a small amount of maleic anhydride (17-18 grams) was added and the reaction was extended until the target was met.

Then, the excess maleic anhydride was removed from the reactor by stripping for 2 hours at 230-235° C. at 60-70 mmHg vacuum.

Example 2 Synthesis of Succinimide

The PIBSA from Example 1 was added to a reactor under nitrogen and heated to 167° C. Then, approximately 300 grams TEPA was added, so that the molar ratio of PIBSA to TEPA was 1.0:1.0. The addition rate of the TEPA to the PIBSA mixture is dependent upon the amount of foaming.

The vacuum is slowly changed to 70 mmHg. The water is then stripped from the reaction for approximately 2.5 hours.

The material is then filtered at 150° C.

The nitrogen content ranged from 6.2-6.4% and the total base number ranged from 140 to 160. Both infrared and carbon ¹³NMR showed the expected carbonyl peaks.

The viscosity of the product at 100 was typically above 2300 cSt.

Example 3 Results of PFI Rig Test

The results of various additive packages are shown below in Table 1. TABLE 1 % Fluid Loss at 44 Additive Treat Rate (PTB) Cycles None 0 32.0 None 0 48.5 Mannich 80 23.8 Detergent* Mannich 80 43.0 Detergent* Mannich 80/3 16.3 Mannich 80/3 6.3 Detergent*/ Succinimide⁺ *The Mannich Detergent package contained 1.6 PTB of a succinimide that was the reaction product of a reaction of PIBSA and TEPA in a 1.6:1.0 molar ratio. ⁺The succinimide used was the reaction product of a reaction of PIBSA and TEPA in a 1.0:1.0 molar ratio. 

1. A gasoline additive composition comprising (a) a Mannich detergent and (b) a succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.
 2. The composition of claim 1, wherein the alkenyl-substituted succinic anhydride has an average molecular weight of about 600 to about
 2000. 3. The composition of claim 1, wherein the alkenyl-substituent group of the alkenyl-substituted succinic anhydride has an average molecular weight of about 200 to about
 2950. 4. The composition of claim 1, wherein the alkenyl-substituted succinic anhydride is polyisobutylene succinic anhydride.
 5. The composition of claim 4, wherein the polyisobutylene succinic anhydride has an average molecular weight of about 600 to about
 2000. 6. The composition of claim 4, wherein the alkenyl-substituent group of the polyisobutylene succinic anhydride has an average molecular weight of about 200 to about
 2950. 7. The composition of claim 1, wherein the amine-containing polyalkylene polymer has an average molecular weight of about 125 to about
 650. 8. The composition of claim 1, wherein the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 4 nitrogen atoms per molecule.
 9. The composition of claim 1, wherein the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 3.0 to about 18.0.
 10. The composition of claim 1, wherein the amine-containing polyalkylene polymer is tetraethylenepentamine.
 11. The composition of claim 1, wherein the alkenyl-substituted succinic anhydride is polyisobutylene succinic anhydride and the amine-containing polyalkylene polymer is tetraethylenepentamine.
 12. The composition of claim 1, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction in a molar ratio of about 1.6:1.0 to about 1.0:1.0.
 13. The composition of claim 1, wherein the Mannich detergent comprises the reaction product of at least one alkyl-substituted hydroxyaromatic compound, an aldehyde and at least one amine.
 14. The composition of claim 13, wherein the alkyl-substituted hydroxyaromatic compound is an alkyl-substituted cresol.
 15. The composition of claim 14, wherein the alkyl-substituted cresol is polybutylphenol.
 16. The composition of claim 15, wherein the polybutylphenol has an average molecular weight of about 750 to about
 1200. 17. The composition of claim 13, wherein the amine comprises at least one aliphatic diamine having one primary or secondary amino group and one tertiary amino group in the molecule.
 18. The composition of claim 17, wherein the amine comprises dibutyl amine.
 19. The composition of claim 13, wherein the aldehyde is formaldehyde.
 20. The composition of claim 13, wherein the alkyl-substituted hydroxyaromatic compound is an alkyl-substituted cresol, the aldehyde is formaldehyde, and the amine is dibutyl amine.
 21. The composition of claim 1, wherein the composition additionally contains at least one additive selected from the group consisting of carrier fluids, friction modifiers, detergents, dispersants, anti-valve-seat reducing agents, combustion improvers, antioxidants, heat stabilizers, anti-icing additives, antiknock additives, corrosion inhibitors, dehazers, metal deactivators, antifoaming agents, biocides, cosolvents, package compatibilisers, lubricity additives, antistatic additives, drag reducing agents, dyes, markers, cold flow additives, and demulsifiers.
 22. A gasoline fuel composition comprising (a) a hydrocarbon, (b) a Mannich detergent and (c) a succinimide that comprises a reaction product of (i) an alkenyl-substituted succinic anhydride having an average molecular weight of about 250 to about 3000 and (ii) an amine-containing polyalkylene polymer having an average molecular weight of about 100 to about 750, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 2.0:1.0 to about 1.0:1.3.
 23. The fuel composition of claim 22, wherein the Mannich detergent and the succinimide are each present in a minor amount.
 24. The fuel composition of claim 22, wherein the hydrocarbon comprises a spark-ignition fuel.
 25. The fuel composition of claim 24, wherein the spark-ignition fuel comprises gasoline.
 26. The fuel composition of claim 25, wherein the spark-ignition fuel comprises a blend of hydrocarbons of the gasoline boiling range and a fuel-soluble oxygenated compound.
 27. The fuel composition of claim 22, wherein the alkenyl-substituted succinic anhydride has an average molecular weight of about 600 to about
 2000. 28. The fuel composition of claim 22, wherein the alkenyl-substituent group of the alkenyl-substituted succinic anhydride has an average molecular weight of about 200 to about
 2950. 29. The fuel composition of claim 22, wherein the alkenyl-substituted succinic anhydride is polyisobutylene succinic anhydride.
 30. The fuel composition of claim 29, wherein the polyisobutylene succinic anhydride has an average molecular weight of about 600 to about
 2000. 31. The fuel composition of claim 29, wherein the alkenyl-substituent group of the polyisobutylene succinic anhydride has an average molecular weight of about 200 to about
 2950. 32. The fuel composition of claim 22, wherein the amine-containing polyalkylene polymer has an average molecular weight of about 125 to about
 650. 33. The fuel composition of claim 22, wherein the amine-containing polyalkylene polymer is a mixture in which the predominant amine-containing polyalkylene polymer contains at least about 4 nitrogen atoms per molecule.
 34. The fuel composition of claim 22, wherein the average number of nitrogen atoms per molecule of the amine-containing polyalkylene polymer is about 3.0 to about 18.0.
 35. The fuel composition of claim 22, wherein the amine-containing polyalkylene polymer is tetraethylenepentamine.
 36. The fuel composition of claim 22, wherein the alkenyl-substituted succinic anhydride is polyisobutylene succinic anhydride and the amine-containing polyalkylene polymer is tetraethylenepentamine.
 37. The fuel composition of claim 22, wherein the alkenyl-substituted succinic anhydride and the amine-containing polyalkylene polymer are present in the reaction at a molar ratio of about 1.6:1.0 to about 1.0:1.0.
 38. The fuel composition of claim 22, wherein the Mannich detergent comprises the reaction product of at least one alkyl-substituted hydroxyaromatic compound, an aldehyde and at least one amine.
 39. The fuel composition of claim 38, wherein the alkyl-substituted hydroxyaromatic compound is an alkyl-substituted cresol.
 40. The fuel composition of claim 39, wherein the alkyl-substituted cresol is polybutylphenol.
 41. The fuel composition of claim 40, wherein the polybutylphenol has an average molecular weight of about 750 to about
 1200. 42. The fuel composition of claim 38, wherein the amine comprises at least one aliphatic diamine having one primary or secondary amino group and one tertiary amino group in the molecule.
 43. The fuel composition of claim 42, wherein the amine comprises dibutyl amine.
 44. The fuel composition of claim 38, wherein the aldehyde is formaldehyde.
 45. The fuel composition of claim 38, wherein the alkyl-substituted hydroxyaromatic compound is an alkyl-substituted cresol, the aldehyde is formaldehyde, and the amine is dibutyl amine.
 46. The fuel composition of 22, wherein the succinimide and the Mannich detergent are each present in an amount that is about 0.5 to about 500 parts per million.
 47. The fuel composition of claim 22, wherein the fuel composition additionally contains an additive selected from the group consisting of carrier fluids, friction modifiers, detergents, dispersants, anti-valve-seat reducing agents, combustion improvers, antioxidants, heat stabilizers, anti-icing additives, antiknock additives, corrosion inhibitors, dehazers, metal deactivators, antifoaming agents, biocides, cosolvents, package compatibilisers, lubricity additives, antistatic additives, drag reducing agents, dyes, markers, cold flow additives, and demulsifiers.
 48. An engine comprising the composition of claim
 1. 49. An engine comprising the fuel composition of claim
 22. 50. A method of preventing gasoline engine injector fouling comprising contacting an injector with the composition of claim
 1. 51. A method of preventing injector fouling comprising contacting an injector with the fuel composition of claim
 22. 52. A method of preventing valve deposits comprising providing the composition of claim
 1. 53. A method of preventing valve deposits comprising providing the fuel composition of claim
 22. 